The elements X, Y, Z and J have the indicated electron configurations starting with the innermost shell. The most metallic element is :

(a) X = 2, 8, 3

(b) Y = 2, 8, 8

(c) Z = 2, 8, 8, 1

(d) j = 2, 8, 8, 7

correct increasing order of density is:

(1)Li<K<Na<Rb<Cs

(2))Li<Na<K<Rb<Cs

(3)Cs<Rb<K<Na<Li

(4)K<Li<Na<Rb<Cs

A common trend to both groups I and II elements in the periodic table, as the atomic number increases are:

(1) oxidizing power increases

(2) atomic radius increases

(3) maximum valency increases

(4) reactivity with water increases

On going down a main subgroup in the periodic table (example Li to Cs in IA or Be to Ba in IIA) the expected trend of change in atomic radius is a :

(a) continuous decrease

(b) continuous increase

(c) periodic one, an increase followed by a decrease

(d) periodic one, a decrease followed by an increase

Lanthanoid contraction is caused due to :

(a) the appreciable shielding on outer electrons by 4f electrons from the nuclear charge

(b) the appreciable shielding on outer electrons by 5d electrons from the nuclear charge

(c) the same effective nuclear charge from Ce to Lu

(d) the imperfect shielding on outer electrons by 4f electrons from the nuclear charge

The outer electron configuration of Gd (Atomic no. 64) is:

(a) 4f³ 5d⁵6d²

(b) 4f⁸ 5d¹⁰6d²

(c) 4f⁴ 5d⁴6d²

(d) 4f⁷ 5d¹6s²

The radius of La³⁺ (at. no. 57) is 1.06 $\stackrel{°}{\mathrm{A}}$ The radius of Lu³⁺ (at.no. 71) might be:

(a) 1.06  $\stackrel{°}{\mathrm{A}}$

(b) 0.85  $\stackrel{°}{\mathrm{A}}$

(c) 1.60  $\stackrel{°}{\mathrm{A}}$

(d) 1.40  $\stackrel{°}{\mathrm{A}}$

Ionic radii are

[2004]

(a) inversely proportional to effective nuclear charge

(b) inversely proportional to square of effective nuclear charge.

(c) directly proportional to effective nuclear charge

(d) directly proportional to square of effective nuclear charge

The correct arrangement of increasing order of atomic radius among Na, K, Mg and Rb is 

(1) Mg<K<Na<Rb

(2) Mg<Na<K<Rb

(3) Mg<Na<Rb<K

(4) Na<K<Rb<Mg

Which of the following is smallest in size?

1. Na⁺

2. F^-

3. O^2-

4. N^3-